Longitudinal Trends in Health-Related Quality of Life, Preventive Health Behaviors, and Handgrip Strength Among Korean Adults (2011–2023): Implications for Active and Digital Preventive Healthcare

Abstract

Background: Korea’s rapid population aging and the prolonged COVID-19 pandemic have intensified the need to
sustain health-related quality of life (HRQoL) through preventive behaviors and functional health maintenance. While
previous research has examined isolated factors such as physical activity or chronic disease, longitudinal evidence linking
behavioral trends and physical function to HRQoL remains limited. Methods: This study analyzed 13 years of nationally
representative data from the Korea National Health and Nutrition Examination Survey (KNHANES, 2011–2023). HRQoL
was measured using the EQ-5D-3L index, and preventive health behaviors included participation in health screening,
influenza vaccination, physical activity, and sedentary time. Handgrip strength (HGS) was assessed using a digital
dynamometer as an objective indicator of physical function. Weighted descriptive statistics, linear trend analyses,
correlation tests, and multiple regression models were applied, adjusting for age, sex, education, income, and chronic
disease status. Results: HRQoL remained generally stable across the study period (mean EQ-5D: 0.940–0.956), with a
temporary decline during the pandemic (2020–2021). Health screening and vaccination rates steadily increased, while
physical activity decreased from 56% to 45% and sedentary time rose by nearly two hours per day. Average handgrip
strength declined gradually—by 5.7% in men and 2.9% in women—especially among older adults. Correlation analysis
revealed that HRQoL was positively associated with physical activity (r = 0.72), handgrip strength (r = 0.75), and health
screening (r = 0.68), and negatively associated with sedentary time (r = –0.61). Multiple regression confirmed handgrip
strength and physical activity as the strongest predictors of HRQoL (Adjusted R² = 0.69). From 2011 to 2023, Korea
experienced a paradoxical pattern of improved biomedical prevention (screening, vaccination) but declining behavioral
health and muscular function. These findings underscore the importance of integrating functional capacity—particularly
handgrip strength—into national preventive healthcare systems. The adoption of IoT-enabled strength and activity
monitoring may enhance early detection of decline, support personalized interventions, and promote active, data-driven
aging in the post-pandemic era.